Apparatus for drying and grinding materials.



ASHER. APPARATUS FOR DRYING AND GRINDING MATERIALS. APPLICATION FILED MATH, 1907.

Patented Aug. 31, 1909.

UNITED STATES PATENT OFFICE.

GOTTLIEB SUTER, 0F BASEL, SWITZERLAND, ASSIGNOR TO THE FIRM 0F SOCIETY OF CHEMICAL INDUSTRY IN BASLE, 0F BASEL, SWITZERLAND.

APPARATUS FOR DRYING AND GRINDING MATERIALS.

To all whom it may concern:

Be it known that I, GoTTLIEB SUTER, a citizen of the Swiss Republic, and resident of Basel, Switzerland, have invented new and useful Improvements in Apparatus for Drying and Grinding Materials, of which the following is a full, clear, and exact specification.

This invention relates to apparatus for drying and grinding materials of any degree of moistness, ranging from a fluid to a solid mass, in a drum which contains grinding bodies of a known kind and into and from which the material is mechanically charged and automatically discharged respectively. The drum, which is open at both ends and has a jacket to receive a hot fluid for heating the drum, rotates in a casing kept Vacuous and arranged for the mechanical charging and the automatic discharging of the material into and from the drum as well as for the exhaust of the steam or vapor from the drum in the direction opposite that wherein the material is traveling.

The accompanying drawing illustrates the invention, Figure 1 being a longitudinal vertical section of the apparatus partly in elevation and Fig. 2 a vertical cross section.

The drum a is open at each end and is journaled and driven in known manner; it contains grinding bodies, which are not shown in the drawing and has a steam jacket 1) whereby it may be heated. It rotates in a stationary casing c which is kept Vacuous with due regard to exclusion of air and for unimpeded admission and discharge of the material to be dried.

The material is fed into the drum as may be necessary for instance, as here shown, by means of rollers (Z and a screw conveyer 6, through the pipe which extends airtight through the end 0 the casing 0, within the drum the material mixes with the heated grinding bodies.

At each end the drum has a sieve r, s, to prevent the grinding bodies from falling out. The sieve s is formed of perforated sheet metal, free from perforations at the part near the periphery of the drum, so that in case the material should be fluid it cannot run out of the drum into the casing o.

The grinding bodies are of suitable size and are made of iron, steel, bronze, stone or the like; they serve to convey the heat from the wall of the drum to the material, to de- Specifieation of Letters Patent.

Application filed May 17, 1907.

Patented Aug. 31, 1909.

Serial No. 374,297.

tach the material which sticks to the wall and to grind the material, the heat developed by the friction aiding the drying operation. The material is gradually forwarded to the delivery opening 9 of the drum whence it is discharged in a dry and ground condition through the chute 79 into the collecting box 72, which is connected airtight with the casing c. When this box is full it can be emptied by opening the valve 2', which is controlled from outside, into a lower box 3', during this operation the vacuum in the drum is maintained by closing the chute p by means of the valve 0, operated from outside the apparatus. The box h with the valves 0 and 71 thus plays the part of an air lock and is therefore provided with the hitherto usual air connecting ducts and intermediate valves, while the lower box j, the interior of which is at atmospheric pressure, serves merely for receiving the dried material, and has a valve 70 operated from the outside so that it may fulfil the function of a discharge look. When the valve 2' is closed and is opened, the dried material falls through a funnel Z into a bucket or screw-conveyer m.

The steam or other vapor is withdrawn from the drum through the exhaust pipe n, so that it travels in the direction opposite that in which the material travels; between the casing and the vacuum pump which effects the exhaustion there may be a surface condenser. Should the vapor be valuable it may be recovered by condensation either in the said condenser or in an apparatus placed behind the vacuum pump.

In the arrangement shown for heating the drum the steam is conducted to the medium of the jacket I) by pipes o, w, m, m, of which w, w and w rotate with the drum a, the condensation water draining away through an enlargement y of the acket, pipes .2, z and q, box t and pipe u; the pipes z, 2 and q rotate with the drum.

The material may be fed into the drum on either continuously or intermittently. For the feeding device illustrated a piston press or any other suitable apparatus may be substituted.

What I claim is:

1. In an apparatus for drying and grind ing materials of any degree of moistness, having a rotatable drum open at both ends,

grinding bodies in said drum, means for mechanically charging said drum with the material, means for discharging the material from the drum b, its rotation in connection with the said m chanical charging means, the combination of the said drum with a heating jacket to receive a hot fluid, a casing surrounding said heating jacket and drum, and means for maintaining a partial vacuum in said casing and exhausting the steam or' vapor from said drum, said charging means and said exhausting means being connected to the casing near the one end of the drum and said discharging means being connected to said casing near the other end of the drum.

2. In an apparatus for drying and grinding materials of any degree of moistness, having-a rotatable drum open at both ends, grinding bodies in said drum, means for mechanically chargin said drum with the material, means for discharging the material from the drum by the rotation of this latter in connection with the said mechanical charging means, the combination of said drum with a. heating. jacket to receive a hot fluid, a casing surrounding said heating jacket and drum, and means for maintaining a partial vacuum in said casing and exhausting the steam or vapor from said drum, said charging means and said exhausting means being connected to the casing near the one end of the drum and said discharging means being connected to said casing near the other end of the drum and provided with a sieve.

In witness whereof I have hereunto signed my name this 24 day of April 1907, in the presence of two subscribing witnesses.

GOTTLIEB SUTER. Vi tn esses Gno. GIFFORD, AMAND BRAUN. 

